Unlike amphibians, reptiles
a. use single-loop circulatory system.
b. have a closed circulation system in which blood circulates entirely within blood vessels.
c. have ventricles that are further divided to lessen mixing of oxygen-rich and oxygen-poor blood.
d. have lungs to oxygenate blood.

Ascientist separates a population of mice into two groups. what would most likely increase the rate of speciation in this population. a. teach the two groups different tricks b. allow the two groups to breed with each other c. put the two groups in different environment d. have the two groups live in identical ecosystems

Which blood cell spend most of their time in the lymphatic system?

Why are common names a problem for scientist?